drm/i915/cnl: Gen10 render context size.

No change on render context size is required for Gen10.

So this patch doesn't change the default behaviour,
but only avoid the missing_case message.

Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Link: http://patchwork.freedesktop.org/patch/msgid/1499375184-5725-1-git-send-email-rodrigo.vivi@intel.com

drivers/gpu/drm/i915/intel_engine_cs.c

@@ -149,6 +149,7 @@ __intel_engine_context_size(struct drm_i915_private *dev_priv, u8 class)
 		switch (INTEL_GEN(dev_priv)) {
 		default:
 			MISSING_CASE(INTEL_GEN(dev_priv));
+		case 10:
 		case 9:
 			return GEN9_LR_CONTEXT_RENDER_SIZE;
 		case 8: